20026-5041
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Permanent Red 372.9

Rembrandt, the world's most popular soft pastels,have an unsurpassed purity and intensity. Rembrandt Pastels are made from the best quality, finely ground, pure pigments in an extra-fine kaolin clay binder. They contain no hard bits or sharp edges.

Permanent Red 372.9

Color Swatches created using heavy to light application and were applied on 100 lb (163 gsm) drawing paper material.

Pigment Type

Chemical Name

Chemical Formula

Properties

Permanence

Diarylide Yellow 83 has very good lightfastness and permanence. However, it can fade in tints, so some artists do not consider it suitable as an artists’ color. Many other diarylide yellow pigments are reported to have fair to poor lightfastness, and some are completely fugitive. Diarylide Yellow 83 is reputed to be one of the most permanent of the entire group.

Toxicity

Diarylide Yellow has no significant acute hazards, but chronic hazards have not been well studied.

History

Diarylide Yellow comes from a family of azo pigments called Diarylide. These yellow hued pigments were developed around 1940 and are very important in printing inks.

Alternate Names

PR254—Pyrrole Red

Pigment Type

organic, aminoketone

Chemical Name

Bis-(p-chrolopheny)-1. 4-diketopyrrolo(3. 4-c)pyrrole

Chemical Formula

n/a

Properties

Pyrrole Red is opaque and has strong covering power. According to manufacturer Ciba, which uses the trade name Irgazin Red, it is a “clean, highly saturated mid shade red with high temperature resistance, excellent color strength, outstanding chemical, solvent and bleed resistance, and good weatherfastness.”

Permanence

Pyrrole Red is considered to have excellent lightfastness among organic pigments in its class. Tests in industrial applications have given it scores of 7-8 on the Blue Wool Scale.

Toxicity

According to the Australian government's Ministry on Health and Aging, "The notified chemical exhibited low oral and dermal toxicity in rats, did not exhibit toxic effects when administered orally to rats for 28 days, was not a skin irritant in rabbits, was not a skin sensitiser in guinea pigs, was not mutagenic in bacteria and was not clastogenic in CHO cells in culture. However, the notified chemical was a slight eye irritant in rabbits. On the basis of submitted data, the notified chemical would not be classsified as hazardous in accordance with Approved Criteria for Classifying Hazardous Substances."

History

Pyrrole Red, used as an automotive paint and as a colorant in plastics, was developed as one of a range of pigments to replace lead based pigments. In art materials, it is often used as a synthetic and lightfast replacement for carmine, a laked pigment that was originally produced from the body of the cochineal insect. It is also used to replace the older naphthol reds, organic red pigments that are sometimes only marginally lightfast and weatherfast.